Study to Evaluate JCXH-211 as Monotherapy in Patients With Malignant Solid Tumors

Inclusion Criteria: * Male or female patients 18-75 * Patients with malignant solid tumors that have been diagnosed by pathology and/or cytology * Patients who have progressed on or who cannot tolerate available therapies or for whom curative therapy does not exist * Patients with at least one non-injected measurable tumor lesion per RECIST v1.1 * Patients with lesions suitable for intratumoral injection (the lesion length is at least 10mm and not exceeding 80mm) * Patients enrolled in the Skin/subcutaneous lesions and deep （visceral） lesions stages of Phase Ia must agree to provide pre- and post-treatment tumor biopsy tissues * Patients must have adequate organ and marrow functions * Patients with treated brain metastases are eligible if meeting protocol's requirement * Patients must be ≥ 4 weeks beyond treatment with any chemotherapy (6 weeks for nitrosoureas or mitomycin C), hormonal, biological, targeted agents, other investigational therapy or radiotherapy Exclusion Criteria: * Patients who have received prior IL-12 either alone or as part of a treatment regimen * Patients who have received prior therapy with an immuno-oncology agent and were discontinued from that treatment due to a Grade 3 or higher immune-related adverse event (irAE) * Patients requiring therapeutic doses of anticoagulation * Patients with tumors that impinge on major airways, blood vessels, or nerve bundles * Patients with a history of autoimmune disease that has the possibility of recurrence or active autoimmune disease that requires immunosuppressive medications * Patients who had a major surgical procedure within 4 weeks prior to the first dose of study treatment * Current or prior use of immunosuppressive medication within 2 weeks prior to the first dose of study treatment * Patient with history of solid organ or allogenic bone marrow transplantation